Major depressive disorder is characterized by a well-documented array of maladaptive cognitive phenomena, but the clinical assessment of depressive cognition has remained largely uninformed by recent methodological and theoretical advances in the domain of cognitive neuroscience. This study examines the application of two prominent cognitive neuroscience techniques that appear to be of great translational promise in the assessment of depressive cognition. Specifically, we will apply (a) divided visual field (DVF) stimulus presentation, which isolates the function of left and right cerebral hemispheres, and (b) analysis of quantitative electroencephalograph (QEEG) event-related potentials (ERP), which provide sensitive detection of cognitive processes reflected in real-time brain events. The study will include depressed outpatients (n = 60), assessed both in-episode and at a 3-month follow-up, as well as social phobic patient controls (n = 30) and never-depressed controls (n = 30). Depressed and social phobic participants will be recruited from a large community mental health center at a rate of approximately 2 per month and 1 per month, respectively, over 2.5 years. All participants will complete, at both assessment time points, the following: 8 brief tasks utilizing the ERP P300 component and DVF to evaluate hemispheric lateralization of selective attention to verbal and nonverbal depression-relevant stimuli, 2 tasks utilizing the ERP P400 component to evaluate the degree to which depressive self statements are perceived as self-congruent, a DVF verbal semantic priming task, and 3 self-report cognitive measures. It is hypothesized, on the basis of pilot data and theoretical considerations, that there will be observed a stable, trait-like negativistic right-hemispheric (RH) processing bias for verbal information among in-episode and fully remitted depressed patients (with positivistic RH bias among controls), and that the DVF/ERP paradigms will prove superior to self-report measures in detecting trait-like depressive cognition. Secondary analysis will explore the ability of study measures to predict acute outcome in outpatient treatment.